This project is part of the BOVA MARINA ARCHAEOLOGICAL PROJECT that aims to explore the history of human habitation in the region of Bova Marina, in SW Calabria, Italy. Its goal is to
explore the logic of ceramic technological decision-making throughout prehistory, by
examining the interactions between environmental, mechanical & functional factors,
social contexts and traditional knowledge in the creation and use of ceramics.

Since 1998, at Umbro in Bova Marina, SW
Calabria (Italy), we have excavated five separate sites within 300m from each
other. Umbro Neolithic is a rock shelter that was in use from 5,800 to
2,900 BC. Penitenzeria is a Neolithic
habitation site used from 5,500 to 5,000 BC. The Umbro Bronze Age site is a habitation and ritual site
dated to ca. 1800-1500, while Sant'Aniceto is a Late Bronze Age house dated to ca. 1260-910 BC. Finally, we have excavated a Classical Greek farmhouse, dating to the late 5th-early 4th century BC.

My project combines a systematic raw materials survey with experimental projects in the field and in the laboratory to explore the distribution of resources on the Calabrian landscape and the mineralogical and physico-chemical properties of available raw materials. Against this systematic and deep understanding of the local materials I study the mineralogy, chemistry and physical structure of the archaeological ceramics, combining petrography, XRD, INAA and SEM. With these data I reconstruct the complete ceramic production sequence within each site and time period and assess the extent to which recipes, manufacturing techniques, etc., persisted or changed across time. The analysis of the geological clays has been published in the Journal of Archaeological Science (Michelaki et al., 2012) and our interpretation of the long-term interplay between the Bova Marina landscape and the local Neolithic potters has appeard in the Journal of Archaeological Method and Theory (Michelaki et al., 2015). We are currently preparing the Neolithic material for publication (Robb and Michelaki, 2012; Michelaki et al., in press.; Michelaki and Robb, in prep.). Analyses of the Bronze Age and Classical material continue and will be completed within the next two years. Independent archaeological data suggest that, during the Late Neolithic, the Early and Late Bronze Ages, and the Greek period, southern Italian communities were re-organized significantly. The types, sizes and distributions of their settlements changed. So did their burial customs, their material culture and their connections with the broader Mediterranean world. Our goal is to test whether ceramic technologies persisted despite social re-organizations. Doing so will allow us to evaluate whether long-term traditions were deeply engrained and powerful factors guiding technological decision-making.

With support from the National Science Foundation, a collaborating team of archaeologists and materials scientists will unite all of the researchers testing and developing the newly-proposed Ceramic Rehydroxylation Dating (RHX) technique, a novel chronometric dating technique with significant potential to revolutionize archaeological practice. Michigan Technological University will lead a team of collaborating archaeologists and materials scientists from Arizona State University, California State University-Long Beach, and Tel Aviv University, and in cooperation with the Universities of Manchester, Edinburgh, and Bradford. The scientists will work collectively to replicate the individual RHX findings using samples of the same fired-clay ceramic artifacts, develop best-practices for sample preparation protocols and data analysis, complete quantitative assessment of the deviation in calculated dates, and refine the model that best describes rehydration/ rehydroxylation process. This grant provides for instrument time and lab costs, graduate and undergraduate student lab assistants, travel, and supervisory time costs. This grant also helps researchers further advance fledgling collaborations at MichiganTechnological University, the Arizona State University, and California State University-Long Beach. The collaborations are based upon research-as-inquiry as an educational model for undergraduate and graduate students in science, technology, engineering, and mathematics (STEM), because archaeological problems require interdisciplinary approaches.

Intellectual Merit:

The rehydroxylation dating technique is potentially revolutionary, because it would be a low-cost method to assign chronometric dates to a nearly ubiquitous artifact type. The technique would also require comparatively inexpensive instrumentation operated by any technically-literate researcher. RHX dating could permit us to formulate research questions of the archaeological record at specific sites which archaeologists otherwise turn to ethnoarchaeology to answer, including questions about technology transfer, landscape learning, and specialized ceramic production in state societies. This research will ultimately provide analytical models that other archaeologists can use alongside those developed in ethnoarchaeology and experimental archaeology when studying ceramic production by specialized workers in antiquity.

Results:

Our lab could not validate the RHX technique as it appeared in the existing literature. We wondered whether one of the reasons why this was happening was that a fundamental assumption of the theory behind the RHX method was not valid. RHX dating assumes that the original firing of the ceramic artifact should set the dating clock to zero by driving all hydroxyls out of the clay chemical structure. To examine whether this assumption holds, especially for pot firings of short duration and low intensity, as those in small-scale traditional settings, we performed thermogravimetric analysis of clay samples of known mineralogy at temperatures and for durations reported from traditional sub-Saharan, American, and South Asian pottery firings. Results demonstrate that in the majority of samples, complete dehydroxylation (DHX) did not occur within, or even beyond, the conditions common in traditional firings. Consequently, between 0.01 and 1.5% of a sample's mass in residual OH may remain after firings analogous to those observed in the ethnographic record. Lack of complete DHX at the scales we have observed can result in the over-estimation of ceramic ages by decades to tens of thousands of years, depending largely on the age of the sample, and the amount of residual OH present. Thus, in many cases, a key assumption underlying current RHX dating methods is unlikely to have been met, introducing considerable error in dates.